As electronic devices continue to evolve, the demands on components in the devices continue to grow. There is an ever-increasing demand to improve accuracy and speed, and reduce cost. One device found in virtually all electronic devices is a memory device. There are different kinds of memories employed for different purposes in various electronic devices. Semiconductor memory devices generally fall into two groups: bipolar and metal oxide semiconductor (MOS) devices. While bipolar memories offer higher speeds, MOS memories are generally less expensive to fabricate and offer higher bit densities. Depending upon their functional use, semiconductor memories can also be categorized as random access read-write memories (RAM) or read-only memories (ROM). The primary difference between these two times the memories is that the data pattern of stored information is fixed in a read-only memory, while it is changed during normal operation in a random access memory.
Random access memories generally comprise both static and dynamic memories. A static random access memory (SRAM) retains the indefinitely as long as the power is supplied to the integrated circuit. In contrast, a dynamic random access memory (DRAM) stores data only temporarily and must be continually rewritten or refreshed. In order to improve the clock speed of a dynamic random access memory, a double data rate synchronous DRAM (DDR SDRAM) was developed. A DDR SDRAM activates output on both the rising and falling edge of the system clock, a rather than on just the rising edge, potentially doubling output. In a DDR SDRAM, an asynchronous read timer is used during a readout in the data path to generate signals to indicate when data is sensed in the secondary sense amplifier (SSA) and offer the read/write data line bus. However, timings constraints in a conventional DDR SDRAM significantly minimize the amount of time available to read data from the memory.
Accordingly, there is a need for an improved memory device and method of reading data from a memory device.